1. Field of the Invention
The invention relates generally to electrical switching apparatus and, more particularly, to a lifting assembly for lifting electrical switching apparatus for placement in an electrical cabinet.
2. Background Information
Electrical switching apparatus for opening and closing electrical distribution circuits are well known in the art. Such electrical switching apparatus includes power circuit breakers and network protectors which provide protection, and electrical switches which are used to energize and deenergize parts of the circuit or to transfer between alternative power sources.
It is also known to house electrical switching apparatus within an electrical cabinet, such as, for example, a switchgear cabinet for the distribution of electrical power from incoming utility lines to electrical loads distributed throughout a building or other facility. Typically, a plurality of electrical switching apparatus, such as power circuit breakers, are removably mounted within a plurality cells in the electrical cabinet. Such electrical switching apparatus may vary in size and may weigh up to several hundred pounds. Therefore, means must be provided to lift the electrical switching apparatus to properly position the electrical switching apparatus for insertion into their respective cells.
It is known to provide a rail mounted lifter positioned on or adjacent a top side of an electrical cabinet for lifting the electrical switching apparatus for insertion into the cells of the electrical cabinet. One such lifter includes a cantilevered portion that extends outwardly from the electrical cabinet where the lifter includes a winch assembly for connecting to and lifting the electrical switching apparatus. The winch assembly includes a spool for winding a cable thereon. It has been found that often the cable does not wind evenly onto the spool of the winch assembly. The cable has a tendency to accumulate on one area of the spool causing sporadic jumping as the spool turns and releases or retracts the cable. This can result in sudden drops to the electrical switch apparatus during lifting. Of course, the uneven winding of the cable on the spool and the resulting sudden drops to the electrical switching apparatus during lifting are undesirable and may possibly result in damage to the electrical switching apparatus and excessive stress and fatigue being applied to the lifter.
It has also been observed that the lifter has a tendency to bind or twist as a result of the load of the electrical switching apparatus being applied on the cantilevered portion of the lifter. This is particularly the situation when the lifter is supporting the weight of the electrical switching apparatus and it is desired to translate or laterally move the lifter along the top of the electrical cabinet.
There is a need, therefore, for an improved lifting assembly for lifting an electrical switching apparatus for placement in an electrical cabinet.
There is also a need for a lifting assembly for lifting an electrical switching apparatus for placement in an electrical cabinet that provides even distribution of the cable on the spool of the winch assembly.
There is a further need for a lifting assembly for lifting an electrical switching apparatus for placement in an electrical cabinet that provides improved lateral stability of the lifting assembly and minimizes binding or twisting of the lifting assembly while supporting the weight of the electrical switching apparatus.
There is yet a further need for an electrical assembly having an electrical cabinet for receiving an electrical switching apparatus having an improved lifting assembly for lifting the electrical switching apparatus for placement in the electrical cabinet.